It has previously been proposed to place elastic inserts at the circumference of pulling rollers, in which the respective elastic inserts are offset with respect to non-elastic or inelastic inserts, see the referenced German Pat. No. 23 57 208. This German patent discloses a roller pair in which the inserts are formed as alternating steel rings and rubber rings to form, alternatingly, ring zones of elastic and, respectively, less elastic or non-elastic material. The arrangement is so made that the non-elastic ring zones of one roller continuously run off with their entire width on the elastic ring zones of the opposite or matching roller. The elastic ring zones always have the same width as the relatively non-elastic ring zones.
It has been found that such a tension roller is expensive to make and leads to substantial wear, particularly due to deformation of the elastic rings in running direction. Due to the differential pairing of the rings, changes in diameter of the elastic rings result in increased kneading action of the elastic material, resulting in substantial heating and wear. Additionally, the printed web is longitudinally deformed, and such longitudinal deformation, for example resulting in slight ridges or grooves or corrugations, may propagate themselves along the moving web, for example up to a folding former. As a result, the web is not uniformly tensioned throughout its entire width, which may interfere with formation of the longitudinal fold over a folding former at a desired transverse position.